//向外导出vuex模块
export default {
	//为当前模块开启命名空间
	namespaced: true,
	
	//模块的state数据
	state: () => ({
		//购物车的数组，用来存储购物车中每个商品的信息对象
		// 每个商品的信息对象，都包含如下 6 个属性：
		// { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
		cartArr: JSON.parse(uni.getStorageSync('cartKey') || '[]'),
	}),
	
	//模块的mutations方法
	mutations: {
		addToCart(state, goods) {
			//根据提交的商品ID，查询购物车中是否存在这件商品
			const findResult = state.cartArr.find( x => x.goods_id === goods.goods_id)

			if (!findResult) {
				state.cartArr.push(goods)
			} else {
				findResult.goods_count++
			}
		
			//通过commit方法，调用m_cart命名空间下的saveToStorage方法
			this.commit('m_cart/saveToStorage')
		},
		
		saveToStorage(state) {
			uni.setStorageSync('cartKey', JSON.stringify(state.cartArr))
		},

		updateGoodsState(state, goods) {
			const findResult = state.cartArr.find(x => x.goods_id === goods.goods_id)
			if (findResult) {
				findResult.goods_state = goods.goods_state
				
				this.commit('m_cart/saveToStorage')
			}
		},
		
		updateGoodsCount(state, goods) {
			const findResult = state.cartArr.find(x => x.goods_id === goods.goods_id)
			if (findResult) {
				findResult.goods_count = goods.goods_count
				this.commit('m_cart/saveToStorage')
			}
		},
		
		deleteGoods(state, goods_id) {
			state.cartArr = state.cartArr.filter(x => x.goods_id !== goods_id)
			this.commit('m_cart/saveToStorage')
		},
		
		updateAllGoodsState(state, newState) {
			state.cartArr.forEach(x => x.goods_state = newState)
			this.commit('m_cart/saveToStorage')
		}
	},
	
	//模块的getters 属性
	getters: {
		total(state) {
			// let count = 0
			// state.cartArr.forEach(goods => count += goods.goods_count)
			// return count

			return state.cartArr.reduce((total, item) => total += item.goods_count, 0)
		},
		
		checkedCount(state) {
			let arr = state.cartArr.filter(x => x.goods_state)
			return arr.reduce((total, item) => total += item.goods_count, 0)
		},
		
		totalPrice(state) {
			 let arr = state.cartArr.filter(x => x.goods_state)
			 return arr.reduce((total, item) => total += item.goods_count * item.goods_price, 0).toFixed(2)
		}
	},
}